Possible impact damage?

Without seeing the extent of the damage or pictures it's hard to say whether they're superficial cracks or serious. I however would repair the bulkheads as they are structural support for the hull.

I loaded a sailboat that the delivery captain had bounced the keel off of the bottom coming in St. Augustine inlet. It seriously cracked several interior bulkheads (completely through on both sides) that were structural support for both the hull sides and deck. It was verified that the damage was not there prior to this as a survey was done a week before when the owner bought the vessel. It's a shame as it was a beautiful j-class (I think) racing sailboat.

J,

J-Boats are fin keeled rather than full keeled and are lightly built for racing, yet are very strong. I've raced on quite a few over the years.

We have a French built boat in the yard at the moment that has suffered similar damage. It is less than a year old but the damage is extensive. The center of the interior has been removed for access and the keel dropped.

All the stringers running from the keel have had to be ground out and repaired, around the chainplate mounts repaired and the bulkhead bonding re-done. A big mess. The keel will need some major surgery too.

On a full keel cruiser, everything is a little heavier laid-up and (I hope) much less damage should have taken place. A full survey is the only way to find the extent of any damage.

It doesn't happen to be red in color and the name starts with "cha______" is it?

Because the bulkhead sounds like it is a lot more rigid then the rest of the hull. The rest of the hull flexed, yet the bulkhead didn't and absorbed the impact and cracked.